It is essential that the headrest, once adjusted to the proper position by the dentist, remain positively locked in that position while the patient is being worked on. It would be most disquieting to the patient and the dentist were this not so. Prior art headrest locking devices, in order to achieve an equivalent degree of positive locking, required critical and/or time-consuming adjustments, or employed metal to metal contact of moving parts which were unnecessarily noisy for the patient.
Accordingly, it is an object of the present invention to provide a positive means for locking a dental headrest in position.
Another object of the invention is to provide such positive locking means which are inexpensive, easy to manufacture, and very rapidly and quietly adjustable.
Still another object of the invention is to provide such positive locking means which are devoid of metal to metal contact of moving parts.
Other objects and a fuller understanding of the invention may be had by referring to the following description and claims taken in conjunction with the accompanying drawings.